Search results for: Mahi Abdelkader
100 Impacts of Climate Change on Water Resources Management in the Mahi River Basin of India
Authors: Y. B. Sharma, K. B. Biswas
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This research project examines a 5000 cal yr BP sediment core record to reveal the consequences of human impact and climate variability on the tropical dry forests of the Mahi river basin, western India. To date there has been little research to assess the impact of climate variability and human impact on the vegetation dynamics of this region. There has also been little work to link changes in vegetation cover to documented changes in the basin hydrology over the past 100 years – although it is assumed that the two are closely linked. The key objective of this research project therefore is to understand the driving mechanisms responsible for the abrupt changes in the Mahi river basin as detailed in historical documentation and its impact on water resource management. The Mahi river basin is located in western India (22° 11’-24° 35’ N 72° 46’-74° 52’ E). Mahi river arises in the Malwa Plateau, Madhya Pradesh near Moripara and flows through the uplands and alluvial plain of Rajasthan and Gujarat provinces before draining into the Gulf of Cambay. Palaeoecological procedures (sedimentology, geochemical analysis, C&N isotopes and fossil pollen evidences) have been applied on sedimentary sequences collected from lakes in the Mahi basin. These techniques then facilitate to reconstruct the soil erosion, nutrient cycling, vegetation changes and climatic variability over the last 5000 years. Historical documentation detailing changes in demography, climate and landscape use over the past 100 years in this region will also be collated to compare with the most recent palaeoecological records. The results of the research work provide a detailed record of vegetation change, soil erosion, changes in aridity, and rainfall patterns in the region over the past 5000 years. This research therefore aims to determine the drivers of change and natural variability in the basin. Such information is essential for its current and future management including restoration.Keywords: human impact, climate variability, vegetation cover, hydrology, water resource management, Mahi river basin, sedimentology, geochemistry, fossil pollen, nutrient cycling, vegetation changes, palaeoecology, aridity, rainfall, drivers of change
Procedia PDF Downloads 36699 Computational Fluid Dynamics (CFD) Modeling of Local with a Hot Temperature in Sahara
Authors: Selma Bouasria, Mahi Abdelkader, Abbès Azzi, Herouz Keltoum
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This paper reports concept was used into the computational fluid dynamics (CFD) code cfx through user-defined functions to assess ventilation efficiency inside (forced-ventilation local). CFX is a simulation tool which uses powerful computer and applied mathematics, to model fluid flow situations for the prediction of heat, mass and momentum transfer and optimal design in various heat transfer and fluid flow processes to evaluate thermal comfort in a room ventilated (highly-glazed). The quality of the solutions obtained from CFD simulations is an effective tool for predicting the behavior and performance indoor thermo-aéraulique comfort.Keywords: ventilation, thermal comfort, CFD, indoor environment, solar air heater
Procedia PDF Downloads 62698 The Impact and Performances of Controlled Ventilation Strategy on Thermal Comfort and Indoor Atmosphere in Building
Authors: Selma Bouasria, Mahi Abdelkader, Abbès Azzi, Herouz Keltoum
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Ventilation in buildings is a key element to provide high indoor air quality. Its efficiency appears as one of the most important factors in maintaining thermal comfort for occupants of buildings. Personal displacement ventilation is a new ventilation concept that combines the positive features of displacement ventilation with those of task conditioning or personalized ventilation. This work aims to study numerically the supply air flow in a room to optimize a comfortable microclimate for an occupant. The room is heated, and a dummy is designed to simulate the occupant. Two types of configurations were studied. The first consist of a room without windows; and the second one is a local equipped with a window. The influence of the blowing speed and the solar radiation coming from the window on the thermal comfort of the occupant is studied. To conduct this study we used the turbulence models, namely the high Reynolds k-e, the RNG and the SST models. The numerical tool used is based on the finite volume method. The numerical simulation of the supply air flow in a room can predict and provide a significant information about indoor comfort.Keywords: local, comfort, thermique, ventilation, internal environment
Procedia PDF Downloads 40597 Transferring World Athletic Championship-Winning Principles to Entrepreneurship: The Case of Abdelkader El Mouaziz
Authors: Abderrahman Hassi, Omar Bacadi, Khaoula Zitouni
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Abdelkader El Mouaziz is a Moroccan long-distance runner with a career-best time of 2:06:46 in the Chicago Marathon. El Mouaziz is a winner of the Madrid Marathon in 1994, the London Marathon in 1999 and 2001, as well as the New York Marathon in 2001. While he was playing for the Moroccan national team, he used to train in the Ifrane-Azrou region owing to its altitude, fresh forests, non-polluted air and quietness. After winning so many international competitions and retiring, he left his native Casablanca and went back to the Ifrane-Azrou region and started a business that employs ten people. In March 2010, El Mouaziz opened a bed and breakfast called Tourtite with a nice view on the mountain near the city of Ifrane in the way to Azrou. He wanted to give back to the region that helped him become a sport legend. His management style is not different than his sport style: performance and competitiveness combined with fair play. The objective of the present case study is to further enhance the understanding of the dynamics of transferring athletic championship-winning principles to entrepreneurial activities. The case study is a real-life situation and experience designed to provoke and stimulate reflections about a particular approach of management, especially for start-up businesses.Keywords: sport, winning principles, entrepreneurship, Abdelkader El Mouaziz
Procedia PDF Downloads 27296 Power Quality Improvement Using Interval Type-2 Fuzzy Logic Controller for Five-Level Shunt Active Power Filter
Authors: Yousfi Abdelkader, Chaker Abdelkader, Bot Youcef
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This article proposes a five-level shunt active power filter for power quality improvement using a interval type-2 fuzzy logic controller (IT2 FLC). The reference compensating current is extracted using the P-Q theory. The majority of works previously reported are based on two-level inverters with a conventional Proportional integral (PI) controller, which requires rigorous mathematical modeling of the system. In this paper, a IT2 FLC controlled five-level active power filter is proposed to overcome the problem associated with PI controller. The IT2 FLC algorithm is applied for controlling the DC-side capacitor voltage as well as the harmonic currents of the five-level active power filter. The active power filter with a IT2 FLC is simulated in MATLAB Simulink environment. The simulated response shows that the proposed shunt active power filter controller has produced a sinusoidal supply current with low harmonic distortion and in phase with the source voltage.Keywords: power quality, shunt active power filter, interval type-2 fuzzy logic controller (T2FL), multilevel inverter
Procedia PDF Downloads 16895 Characterization of the in 0.53 Ga 0.47 as n+nn+ Photodetectors
Authors: Fatima Zohra Mahi, Luca Varani
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We present an analytical model for the calculation of the sensitivity, the spectral current noise and the detectivity for an optically illuminated In0.53Ga0.47As n+nn+ diode. The photocurrent due to the excess carrier is obtained by solving the continuity equation. Moreover, the current noise level is evaluated at room temperature and under a constant voltage applied between the diode terminals. The analytical calculation of the current noise in the n+nn+ structure is developed. The responsivity and the detectivity are discussed as functions of the doping concentrations and the emitter layer thickness in one-dimensional homogeneous n+nn+ structure.Keywords: detectivity, photodetectors, continuity equation, current noise
Procedia PDF Downloads 63594 Nasopharyngeal Cancer in Children and Adolescents: Experience of Emir Abdelkader Cancer Center of Oran Algeria
Authors: Taleb L., Benarbia M., Brahmi M., Belmiloud H., Boukerche A.
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Introduction and purpose of the study: Cavum cancer in children and adolescents is rare and represents 8% of all nasopharyngeal cancers treated in our department. Our objective is to study its epidemiological, clinical, therapeutic, and evolutionary particularities. Material and methods: Retrospective study of 39 patients under 20 years old, treated for undifferentiated non-metastatic carcinoma of the nasopharynx at the Emir Abdelkader Cancer Center between 2014 and 2020. Results and statistical analysis: Median age was 14 years [7-19 years], with a sex ratio of 2.9. The median time to diagnosis was 5.6 months [1 to 14 months], the circumstances of the discovery of which were dominated by lymph node syndrome in 43.6% of cases (n=17) followed by a rhinological syndrome in 30.8% of cases (n=13). The tumor stage was T1 for two patients (5.1%), T2 for 8 (20.5%), T3 for 9 (23.1%), T4 for 20 (51.3%), N0 for 2 (5 .1%) N1 for 4 (10.3%), N2 for 28 (71.8%) and N3 for 5 (12.8%). All patients received induction chemotherapy followed by concomitant radiotherapy with cisplatin. The dose of irradiation delivered to the cavum and adenopathies was 66 Gy with fractionation of 2 Gy per session in 69.2% of cases (n=27) and 1.8 Gy in 30.8% of cases (n=12). With a median follow-up of 51 months (15 to 97 months), the locoregional, metastatic, specific, and overall relapse-free survival rates at five years were 91.1%, 73.5%, 66.1%, and 68.4, respectively. Conclusion: Chemotherapy and radiotherapy treatment of cavum cancer in children and adolescents has allowed excellent locoregional control despite the advanced stage of the disease. However, the frequency of metastatic relapses could justify the possible use of systemic maintenance treatment.Keywords: cancer, nasopharynx, radiotherapy, chemotherapy, survival
Procedia PDF Downloads 10693 Texture Characteristics and Depositional Environment of the Lower Mahi River Sediment, Mainland Gujarat, India
Authors: Shazi Farooqui, Anupam Sharma
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The Mahi River (~600km long) is an important west flowing the river of Central India. It originates in Madhya Pradesh and starts flowing in NW direction and enters into the state of Rajasthan. It flows across southern Rajasthan and then enters into Gujarat and finally debouches in the Gulf of Cambay. In Gujarat state, it flows through all four geomorphic zones i.e. eastern upland zone, shallow buried piedmont zone, alluvial zone and coastal zone. In lower reaches and particularly when it is flowing under the coastal regime, it provides an opportunity to study – 1. Land–Sea interaction and role of relative sea level changes, 2. Coastal/estuarine geological process, 3. Landscape evolution in marginal areas and so on. The Late Quaternary deposits of Mainland Gujarat is appreciably studied by Chamyal and his group of MS University of Baroda, and they have established that the 30-35m thick sediment package of the Mainland Gujarat is comprised of marine, fluvial and aeolian sediments. It is also established that in the estuarine zone, the upper few meter thick sediments package is of marine nature. However, its thickness, characters and the depositional environment including the role of climate and tectonics is still not clearly defined. To understand few aspects of the above mentioned, in the present study, a 17m subsurface sediment core has been retrieved from the estuarine zone of Mahi river basin. The Multiproxy studies which include the textural analysis (grain size), Loss on ignition (LOI), Bulk and clay mineralogy and geochemical studies have been carried out. In the entire sedimentary sequence, the grain size largely varies from coarse sand to clay; however, a solitary gravel bed is also noticed. The lower part (depth 9-17m), is mainly comprised of sub equal proportion of sand and silt. The sediments mainly have bimodal and leptokurtic distribution and deposited in alternate sand-silt package, probably indicating flood deposits. Relatively low moisture (1.8%) and organic carbon (2.4%) with increased carbonate values (12%) indicate that conditions must have to remain oxidizing. The middle part (depth 9–6m) has a 1m thick gravel bed at the bottom and overlain by coarse sand to very fine sand showing fining upward sequence. The presence of gravel bed suggests some kind of tectonic activity resulting into change in base level or enhanced precipitation in the catchment region. The upper part (depth 6–0m; top part of sequence) mainly comprised of fine sand to silt size grains (with appreciable clay content). The sediment of this part is Unimodal and very leptokurtic in nature suggesting wave and winnowing process and deposited in low energy suspension environment. This part has relatively high moisture (2.1%) and organic carbon (2.7%) with decreased carbonate content (4.2%) indicating change in the depositional environment probably under estuarine conditions. The presence of chlorite along with smectite clay mineral further supports the significant marine contribution in the formation of upper part of the sequence.Keywords: grain size, statistical analysis, clay minerals, late quaternary, LOI
Procedia PDF Downloads 17292 Phosphorous Acid: An Efficient and Recyclable Liquid Catalyst for the Synthesis of α-Aminophosphonates
Authors: Hellal Abdelkader, Chafaa Salah, Touafri Lasnouni
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A simple, efficient and general method has been developed for the high diastereoselective synthesis of diethyl α-aminophosphonates in water through “one-pot” three-component reaction of aromatic aldehydes, aminophenols and dialkyl phosphites in the presence of a low catalytic amount (10mol%) of phosphorous acid as highly stable catalyst is described.Keywords: DFT, HOMO-LUMO, phosphonic acid, aminophenols
Procedia PDF Downloads 37491 Place of Radiotherapy in the Treatment of Intracranial Meningiomas: Experience of the Cancer Center Emir Abdelkader of Oran Algeria
Authors: Taleb L., Benarbia M., Boutira F. M., Allam H., Boukerche A.
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Introduction and purpose of the study: Meningiomas are the most common non-glial intracranial tumors in adults, accounting for approximately 30% of all central nervous system tumors. The aim of our study is to determine the epidemiological, clinical, therapeutic, and evolutionary characteristics of a cohort of patients with intracranial meningioma treated with radiotherapy at the Emir Abdelkader Cancer Center in Oran. Material and methods: This is a retrospective study of 44 patients during the period from 2014 to 2020. The overall survival and relapse-free survival curves were calculated using the Kaplan-Meier method. Results and statistical analysis: The median age of the patients was 49 years [21-76 years] with a clear female predominance (sex ratio=2.4). The average diagnostic delay was seven months [2 to 24 months], the circumstances of the discovery of which were dominated by headaches in 54.5% of cases (n=24), visual disturbances in 40.9% (n=18), and motor disorders in 15.9% (n=7). The seat of the tumor was essentially at the level of the base of the skull in 52.3% of patients (n=23), including 29.5% (n=13) at the level of the cavernous sinus, 27.3% (n=12) at the parasagittal level and 20.5% (n=9) at the convexity. The diagnosis was confirmed surgically in 36 patients (81.8%) whose anatomopathological study returned in favor of grades I, II, and III in respectively 40.9%, 29.5%, and 11.4% of the cases. Radiotherapy was indicated postoperatively in 45.5% of patients (n=20), exclusive in 27.3% (n=12) and after tumor recurrence in 27.3% of cases (n=18). The irradiation doses delivered were as follows: 50 Gy (20.5%), 54 Gy (65.9%), and 60 Gy (13.6%). With a median follow-up of 69 months, the probabilities of relapse-free survival and overall survival at three years are 93.2% and 95.4%, respectively, whereas they are 71.2% and 80.7% at five years. Conclusion: Meningiomas are common primary brain tumors. Most often benign but can also progress aggressively. Their treatment is essentially surgical, but radiotherapy retains its place in specific situations, allowing good tumor control and overall survival.Keywords: diagnosis, meningioma, surgery, radiotherapy, survival
Procedia PDF Downloads 9590 Control and Automation of Sensors in Metering System of Fluid
Authors: Abdelkader Harrouz, Omar Harrouz, Ali Benatiallah
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This paper is to present the essential definitions, roles and characteristics of automation of metering system. We discuss measurement, data acquisition and metrological control of a signal sensor from dynamic metering system. After that, we present control of instruments of metering system of fluid with more detailed discussions to the reference standards.Keywords: communication, metering, computer, sensor
Procedia PDF Downloads 54689 Agglomerative Hierarchical Clustering Using the Tθ Family of Similarity Measures
Authors: Salima Kouici, Abdelkader Khelladi
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In this work, we begin with the presentation of the Tθ family of usual similarity measures concerning multidimensional binary data. Subsequently, some properties of these measures are proposed. Finally, the impact of the use of different inter-elements measures on the results of the Agglomerative Hierarchical Clustering Methods is studied.Keywords: binary data, similarity measure, Tθ measures, agglomerative hierarchical clustering
Procedia PDF Downloads 47388 Control of Hybrid System Using Fuzzy Logic
Authors: Faiza Mahi, Fatima Debbat, Mohamed Fayçal Khelfi
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This paper proposes a control approach using Fuzzy Lo system. More precisely, the study focuses on the improvement of users service in terms of analysis and control of a transportation system their waiting times in the exchange platforms of passengers. Many studies have been developed in the literature for such problematic, and many control tools are proposed. In this paper we focus on the use of fuzzy logic technique to control the system during its evolution in order to minimize the arrival gap of connected transportation means at the exchange points of passengers. An example of illustration is worked out and the obtained results are reported. an important area of research is the modeling and simulation ordering system. We describe an approach to analysis using Fuzzy Logic. The hybrid simulator developed in toolbox Matlab consists calculation of waiting time transportation mode.Keywords: Fuzzy logic, Hybrid system, Waiting Time, Transportation system, Control
Procedia PDF Downloads 54787 Investigation Of Eugan's, Optical Properties With Dft
Authors: Bahieddine. Bouabdellah, Benameur. Amiri, Abdelkader.nouri
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Europium-doped gallium nitride (EuGaN) is a promising material for optoelectronic and thermoelectric devices. This study investigates its optical properties using density functional theory (DFT) with the FP-LAPW method and MBJ+U correction. The simulation substitutes a gallium atom with europium in a hexagonal GaN lattice (6% doping). Distinct absorption peaks are observed in the optical analysis. These results highlight EuGaN's potential for various applications and pave the way for further research on rare earth-doped materials.Keywords: eugan, fp-lapw, dft, wien2k, mbj hubbard
Procedia PDF Downloads 5286 Evolution of Mineral Nutrition in Two Species of Atriplex (halimus and canescens) under Salt Stress
Authors: Z. Mahi, L. Marousset, C. Roudaut, M. Belkhodja, R. Lemoine
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The strong accumulation of salts in the soil as well as in irrigation water greatly disrupts the growth and development of almost all plants. The study of these disturbances in halophytes helps provide better guidance on the deteriorating effect of salinity. Evaluation of salt stress in two species of Atriplex (halimus and canescens) through the study of mineral nutrition (dosage of sodium and potassium) shows a variability of responses. The results show that the Na+ ion accumulates in the three organs whatever the applied concentration. This accumulation increases with the high salt concentrations in halimus whereas in canescens, 600 mM treatment shows a reduction of the amount of this element. A decrease in the amount of potassium is observed for all organs except halimus rods 100 mM. Unlike halimus, canescens K + accumulates in high concentrations of salt at the roots and leaves. The ratio Na+/K+ decreases the salt by halimus against it increases in levels canescens roots and treated with high concentrations of NaCl (600 mM) leaves.Keywords: Atriplex, canescens, halimus, Na +, K +, Na Cl, tolerance
Procedia PDF Downloads 34685 Analytical Response Characterization of High Mobility Transistor Channels
Authors: F. Z. Mahi, H. Marinchio, C. Palermo, L. Varani
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We propose an analytical approach for the admittance response calculation of the high mobility InGaAs channel transistors. The development of the small-signal admittance takes into account the longitudinal and transverse electric fields through a pseudo two-dimensional approximation of the Poisson equation. The total currents and the potentials matrix relation between the gate and the drain terminals determine the frequency-dependent small-signal admittance response. The analytical results show that the admittance spectrum exhibits a series of resonant peaks corresponding to the excitation of plasma waves. The appearance of the resonance is discussed and analyzed as functions of the channel length and the temperature. The model can be used, on one hand, to control the appearance of plasma resonances, and on the other hand, can give significant information about the admittance phase frequency dependence.Keywords: small-signal admittance, Poisson equation, currents and potentials matrix, the drain and the gate terminals, analytical model
Procedia PDF Downloads 53684 Intelligent Control Design of Car Following Behavior Using Fuzzy Logic
Authors: Abdelkader Merah, Kada Hartani
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A reference model based control approach for improving behavior following car is proposed in this paper. The reference model is nonlinear and provides dynamic solutions consistent with safety constraints and comfort specifications. a robust fuzzy logic based control strategy is further proposed in this paper. A set of simulation results showing the suitability of the proposed technique for various demanding cenarios is also included in this paper.Keywords: reference model, longitudinal control, fuzzy logic, design of car
Procedia PDF Downloads 42283 Living by the Maramataka: Mahi Maramataka, Indigenous Environmental Knowledge Systems and Wellbeing
Authors: Ayla Hoeta
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The focus of this research is mahi Maramataka, ‘the practices of Maramataka’ as a traditional and evolving knowledge system and its connection to whaanau oranga (wellbeing) and healing. Centering kaupapa Maaori methods and knowledge this research will explore how Maramataka can be used as a tool for oranga and healing for whaanau to engage with different environments aligned with Maramataka flow and optimal time based on the environment. Maramataka is an ancestral lunar environmental knowledge system rooted within korero tuku iho, Maaori creation stories, dating back to the beginning of time. The significance of Maramataka is the ancient environmental knowledge and the connecting energy flow of mauri (life force) between whenua (land), moana (ocean) and rangi (sky). The lunar component of the Maramataka is widely understood and highlights the different phases of the moon. Each moon phase is named with references to puurakau stories and environmental and ecological information. Marama, meaning moon and taka, meaning cycle, is used as a lunar and environmental calendar. There are lunar phases that are optimal for specific activities, such as the Tangaroa phase, a time of abundance and productivity and ocean-based activities like fishing. Other periods in the Maramataka, such as Rakaunui (full moon), connect the highest tides and highest energy of the lunar cycle, ideal for social, physical activity and particularly planting. Other phases like Tamatea are unpredictable whereas Whiro (new moon/s) is reflective, deep and cautious during the darkest nights. Whaanau, particularly in urban settings have become increasingly disconnected from the natural environment, the Maramataka has become a tool that they can connect to which offers an alternative to dominant perspectives of health and is an approach that is uniquely Maaori. In doing so, this research will raise awareness of oranga or lack of oranga, and lived experience of whaanau in Tamaki Makaurau - Aotearoa, on a journey to revival of Maramataka and healing. The research engages Hautu Waka as a methodology using the methods of ancient kaupapa Māori practises based on wayfinding and attunement with the natural environment. Using ancient ways of being, knowing, seeing and doing the Hautu Waka will centre kaupapa Maaori perspectives to process design, reflection and evaluation. The methods of Hautu Waka consists of five interweaving phases, 1) Te Rapunga (the search) in infinite potential, 2) Te Kitenga (the seeing), observations of and attunement to tohu 3) te whainga (the pursuit) and deeply exploring key tohu 4) te whiwhinga (the acquiring), of knowledge and clearer ideas, 5) Te Rawenga (the celebration), reflection and acknowledgement of the journey and achievements. This research is an expansion from my creative practices across whaanau-centred inquiry, to understand the benefits of Maramataka and how it can be embodied and practised in a modern-day context to support oranga and healing. Thus, the goal is to work with kaupapa Maaori methodologies to authenticate as a Maaori practitioner and researcher and allow an authentic indigenous approach to the exploration of Maramataka and through a kaupapa Maaori lens.Keywords: maramataka (Maaori calendar), tangata (people), taiao (environment), whenua (land), whaanau (family), hautu waka (navigation framework)
Procedia PDF Downloads 6482 Global Optimization: The Alienor Method Mixed with Piyavskii-Shubert Technique
Authors: Guettal Djaouida, Ziadi Abdelkader
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In this paper, we study a coupling of the Alienor method with the algorithm of Piyavskii-Shubert. The classical multidimensional global optimization methods involves great difficulties for their implementation to high dimensions. The Alienor method allows to transform a multivariable function into a function of a single variable for which it is possible to use efficient and rapid method for calculating the the global optimum. This simplification is based on the using of a reducing transformation called Alienor.Keywords: global optimization, reducing transformation, α-dense curves, Alienor method, Piyavskii-Shubert algorithm
Procedia PDF Downloads 49681 Analytical Terahertz Characterization of In0.53Ga0.47As Transistors and Homogenous Diodes
Authors: Abdelmadjid Mammeri, Fatima Zohra Mahi, Luca Varani, H. Marinchoi
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We propose an analytical model for the admittance and the noise calculations of the InGaAs transistor and diode. The development of the small-signal admittance takes into account the longitudinal and transverse electric fields through a pseudo two-dimensional approximation of the Poisson equation. The frequency-dependent of the small-signal admittance response is determined by the total currents and the potentials matrix relation between the gate and the drain terminals. The noise is evaluated by using the real part of the transistor/diode admittance under a small-signal perturbation. The analytical results show that the admittance spectrum exhibits a series of resonant peaks corresponding to the excitation of plasma waves. The appearance of the resonance is discussed and analyzed as functions of the channel length and the temperature. The model can be used, on one hand; to control the appearance of the plasma resonances, and on other hand; can give significant information about the noise frequency dependence in the InGaAs transistor and diode.Keywords: InGaAs transistors, InGaAs diode, admittance, resonant peaks, plasma waves, analytical model
Procedia PDF Downloads 30480 Reliability-Simulation of Composite Tubular Structure under Pressure by Finite Elements Methods
Authors: Abdelkader Hocine, Abdelhakim Maizia
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The exponential growth of reinforced fibers composite materials use has prompted researchers to step up their work on the prediction of their reliability. Owing to differences between the properties of the materials used for the composite, the manufacturing processes, the load combinations and types of environment, the prediction of the reliability of composite materials has become a primary task. Through failure criteria, TSAI-WU and the maximum stress, the reliability of multilayer tubular structures under pressure is the subject of this paper, where the failure probability of is estimated by the method of Monte Carlo.Keywords: composite, design, monte carlo, tubular structure, reliability
Procedia PDF Downloads 45679 On the Efficiency of the Algerian FRR Sovereign Fund
Authors: Abdelkader Guendouz, Fatima Zohra Adel
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Since about two decades, the Algerian government created a new instrument in the field of its fiscal policy, which is the FRR (Fonds de Régulation des Recettes). The FRR is a sovereign fund, which the initial role was saving the surplus generated by the fixation of a referential oil price to establish the state budget in the aim equilibrium between budgetary incomes and public expenditures. After a while, the government turns to use this instrument in boosting the public investment more than keeping for funding a deficit budget in periods of crisis. This lead to ask some justified questions about the efficiency of this sovereign fund and its real role.Keywords: FRR sovereign fund, public expenditures, public investment, efficiency
Procedia PDF Downloads 32378 Optimizing the Probabilistic Neural Network Training Algorithm for Multi-Class Identification
Authors: Abdelhadi Lotfi, Abdelkader Benyettou
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In this work, a training algorithm for probabilistic neural networks (PNN) is presented. The algorithm addresses one of the major drawbacks of PNN, which is the size of the hidden layer in the network. By using a cross-validation training algorithm, the number of hidden neurons is shrunk to a smaller number consisting of the most representative samples of the training set. This is done without affecting the overall architecture of the network. Performance of the network is compared against performance of standard PNN for different databases from the UCI database repository. Results show an important gain in network size and performance.Keywords: classification, probabilistic neural networks, network optimization, pattern recognition
Procedia PDF Downloads 25577 Effect of the Fluid Temperature on the Crude Oil Fouling in the Heat Exchangers of Algiers Refinery
Authors: Rima Harche, Abdelkader Mouheb
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The Algiers refinery as all the other refineries always suffers from the problem of stopping of the tubes of heat exchanger. For that a study experimental of this phenomenon was undertaken in site on the cell of heat exchangers E101 (E101 CBA and E101 EDF) intended for the heating of the crude before its fractionation, which are exposed to the problem of the fouling on the side tubes exchangers. It is of tube-calenders type with head floating. Each cell is made up of three heat exchangers, laid out in series.Keywords: fouling, fluid temperatue , oil, tubular heat exchanger, fouling resistance, modeling, heat transfer coefficient
Procedia PDF Downloads 42476 Data Mining in Medicine Domain Using Decision Trees and Vector Support Machine
Authors: Djamila Benhaddouche, Abdelkader Benyettou
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In this paper, we used data mining to extract biomedical knowledge. In general, complex biomedical data collected in studies of populations are treated by statistical methods, although they are robust, they are not sufficient in themselves to harness the potential wealth of data. For that you used in step two learning algorithms: the Decision Trees and Support Vector Machine (SVM). These supervised classification methods are used to make the diagnosis of thyroid disease. In this context, we propose to promote the study and use of symbolic data mining techniques.Keywords: biomedical data, learning, classifier, algorithms decision tree, knowledge extraction
Procedia PDF Downloads 54975 Sizing of Hybrid Source Battery/Supercapacitor for Automotive Applications
Authors: Laid Degaa, Bachir Bendjedia, Nassim Rizoug, Abdelkader Saidane
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Energy storage system is a key aspect for the development of clean cars. The work proposed here deals with the modeling of hybrid storage sources composed of a combination of lithium-ion battery and supercapacitors. Simulation results show the performance of the active model for a hybrid source and confirm the feasibility of our approach. In this context, sizing of the electrical energy supply is carried out. The aim of this sizing is to propose an 'optimal' solution that improves the performance of electric vehicles in term of weight, cost and aging.Keywords: battery, electric vehicles, energy, hybrid storage, supercapacitor
Procedia PDF Downloads 78674 Bi-Functional Natural Carboxylic Acid Catalysts for the Synthesis of Diethyl α-Aminophosphonates in Aqueous Media
Authors: Hellal Abdelkader, Chafaa Salah, Boudjemaa Fouzia
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A new, convenient, and high yielding procedure for the preparation of diethyl α-aminophosphonates in water via Kabachnik-Fields reaction by one-pot reaction of aromatic aldehydes, ortho-aminophenols, and dialkylphosphites in the presence of a low catalytic amount of citric, malic, tartaric, and oxalic acids as a natural, bi-functional, and highly stable catalyst is described, the obtained products were characterized by elemental analyses, molar conductance, magnetic susceptibility, FTIR, Uv-Vis spectral data, NMR-C, NMR-H, and NMR-P analyses.Keywords: α-aminophosphonates, aminophenols, natural acids, aqueous media, Kabachnik-Fields reaction
Procedia PDF Downloads 32673 Size Distribution Effect of InAs/InP Self–Organized Quantum Dots on Optical Properties
Authors: Abdelkader Nouri, M’hamed Bouslama, Faouzi Saidi, Hassan Maaref, Michel Gendry
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Self-organized InAs quantum dots (QDs) have been grown on 3,1% InP (110) lattice mismatched substrate by Solid Source Molecular Beam Epitaxy (SSMBE). Stranski-Krastanov mode growth has been used to create self-assembled 3D islands on InAs wetting layer (WL). The optical quality depending on the temperature and power is evaluated. In addition, Atomic Force Microscopy (AFM) images shows inhomogeneous island dots size distribution due to temperature coalescence. The quantum size effect was clearly observed through the spectra photoluminescence (PL) shape.Keywords: AFM, InAs QDs, PL, SSMBE
Procedia PDF Downloads 67972 Postoperative Radiotherapy in Cancers of the Larynx: Experience of the Emir Abdelkader Cancer Center of Oran, about 89 Cases
Authors: Taleb Lotfi, Benarbia Maheidine, Allam Hamza, Boutira Fatima, Boukerche Abdelbaki
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Introduction and purpose of the study: This is a retrospective single-center study with an analytical aim to determine the prognostic factors for relapse in patients treated with radiotherapy after total laryngectomy with lymph node dissection for laryngeal cancer at the Emir Abdelkader cancer center in Oran (Algeria). Material and methods: During the study period from January 2014 to December 2018, eighty-nine patients (n=89) with squamous cell carcinoma of the larynx were treated with postoperative radiotherapy. Relapse-free survival was studied in the univariate analysis according to pre-treatment criteria using Kaplan-Meier survival curves. We performed a univariate analysis to identify relapse factors. Statistically significant factors have been studied in the multifactorial analysis according to the Cox model. Results and statistical analysis: The average age was 62.7 years (40-86 years). It was a squamous cell carcinoma in all cases. Postoperatively, the tumor was classified as pT3 and pT4 in 93.3% of patients. Histological lymph node involvement was found in 36 cases (40.4%), with capsule rupture in 39% of cases, while the limits of surgical excision were microscopically infiltrated in 11 patients (12.3%). Chemotherapy concomitant with radiotherapy was used in 67.4% of patients. With a median follow-up of 57 months (23 to 104 months), the probabilities of relapse-free survival and five-year overall survival are 71.2% and 72.4%, respectively. The factors correlated with a high risk of relapse were locally advanced tumor stage pT4 (p=0.001), tumor site in case of subglottic extension (p=0.0003), infiltrated surgical limits R1 (p=0.001), l lymph node involvement (p=0.002), particularly in the event of lymph node capsular rupture (p=0.0003) as well as the time between surgery and adjuvant radiotherapy (p=0.001). However, in the subgroup analysis, the major prognostic factors for disease-free survival were subglottic tumor extension (p=0.001) and time from surgery to adjuvant radiotherapy (p=0.005). Conclusion: Combined surgery and postoperative radiation therapy are effective treatment modalities in the management of laryngeal cancer. Close cooperation of the entire cervicofacial oncology team is essential, expressed during a multidisciplinary consultation meeting, with the need to respect the time between surgery and radiotherapy.Keywords: laryngeal cancer, laryngectomy, postoperative radiotherapy, survival
Procedia PDF Downloads 9671 Modeling and Simulation of InAs/GaAs and GaSb/GaAS Quantum Dot Solar Cells in SILVACO TCAD
Authors: Fethi Benyettou, Abdelkader Aissat, M. A. Benammar
Abstract:
In this work, we use Silvaco TCAD software for modeling and simulations of standard GaAs solar cell, InAs/GaAs and GaSb/GaAs p-i-n quantum dot solar cell. When comparing 20-layer InAs/GaAs, GaSb/GaAs quantum dots solar cells with standard GaAs solar cell, the conversion efficiency in simulation results increased from 16.48 % to 22.6% and 16.48% to 22.42% respectively. Also, the absorption range edge of photons with low energies extended from 900 nm to 1200 nm.Keywords: SILVACO TCAD, the quantum dot, simulation, materials engineering
Procedia PDF Downloads 483