Guendouzi A.,Saida University |
Mekelleche S.M.,Abou Bekr Belkaid University Tlemcen
Chemistry and Physics of Lipids | Year: 2012
The aim of these works present in this paper consisted in the development and evaluation of quantitative structure property models (QSPR) for the prediction of the melting points of a series constituted by 62 fatty acids. The best multilinear regressions method (MLR) is used to develop models for the prediction of the melting points. The descriptors of the model are selected among an extended set of more than 500 descriptors (constitutional, topological, geometric, quantum chemical and thermodynamic descriptors). Applicability domains were defined and the predictive power was determined using a set of validations The QSPR models are established using the BMLR method implemented in CODESSA software, It turns out that the best QSPR model (R 2 = 0.948, Radj2=0.936, SD = 0.940 and F-test = 190.90) is obtained with five molecular descriptors.
Chrif L.,Saida University |
Kadda Z.M.,University of Science and Technology of Oran
Procedia Engineering | Year: 2014
This paper, describes a LQG and LQR robust controller for the lateral and longitudinal flight dynamics of an aircraft control system. The controller is used in order to achieve robust stability and good dynamic performance against the variation of aircraft parameters. The application of the proposed LQG and LQR robust control scheme is implemented through the simulation. The proposed robust controller for aircraft stability is designed using Matlab/Simulink program. Simulation results confirm the performance of the proposed controller for aircraft control system. Since the time of its introduction, the Kalman filter has been the subject of extensive research and application, particularly in the area of autonomous or assisted navigation. For example, to determine the velocity of an aircraft or sideslip angle, one could use a Doppler radar, the velocity indications of an inertial navigation system, or the relative wind information in the air data system. Rather than ignore any of these outputs, a Kalman filter could be built to combine all of this data and knowledge of the various systems dynamics to generate an overall best estimate of pitch, roll and sideslip angle. © 2014 Published by Elsevier Ltd.
Abdelkader E.,University of Science and Technology of Oran |
Nadjia L.,Saida University |
Ahmed B.,University of Science and Technology of Oran
Applied Surface Science | Year: 2012
A novel nanoscale powder 20 wt%SrO-CuBi 2O 4 has been successfully synthesized for the first time by ion exchange through doping Sr(NO 3) 2 into CuBi 2O 4 matrix and characterized using TG/DTA, XRD, EDX, SEM and electrical measurements. The as-prepared 20 wt%SrO-CuBi 2O 4 composite exhibit much higher photocatalytic activity than 20 wt%SrO-CuBi 2O 4 synthesized via physical process and pure phase CuBi 2O 4 under UV-A light irradiation (λ = 365 nm) in the course of the photocatalytic redox activity of Congo red (CR). Maximum degradation was achieved within 220 min of irradiation time under UV-A light as a result of 97.22% of photocatalytic efficiency of CR. The mechanisms of the enhancement of photocatalytic activity of the nanocomposite photocatalyst will be discussed by the p-n heterojunction principle (charge separation and photochemical diode models) and the valance band theory. The pure nanocomposite systems have been also reported for a comparative purpose. © 2011 Elsevier B.V. All rights reserved.
Mekri F.,Saida University |
Elghali S.B.,Aix - Marseille University |
Benbouzid M.E.H.,CNRS Brest Laboratory of Mechanics and Systems Laboratory
IEEE Transactions on Sustainable Energy | Year: 2013
This paper deals with the use of permanent magnet multiphase generators in marine current turbines with the aim to highlight their fault-tolerance. In this context, the performances and the fault-tolerant capabilities of a five-phase permanent magnet synchronous generator are evaluated within a marine current turbine and compared to a classical three-phase generator. For both topologies, a robust nonlinear control strategy is adopted. The adopted control consists of an adaptive control approach that combines three strategies: a maximum power point tracking (MPPT), an optimal fault-adaptive reference current generation, and high-order sliding modes. Simulations are carried-out using a Matlab/Simulink-based marine current turbine simulator to analyze the generator performances during open-circuit faults. Conclusions are then derived regarding multiphase generators' key features for marine applications. © 2010-2012 IEEE.
Shamseddine A.I.,American University of Beirut |
Farhat F.S.,Saida University
Chemotherapy | Year: 2011
The role of platinum-based compounds (PBCs) in the treatment of metastatic breast cancer (MBC) has been extensively studied. As single agents, high response rates have been observed in first-line therapy, while results in pretreated patients were discouraging. Regimens containing cisplatin/carboplatin together with taxanes showed the highest efficacy and safety as both first-line and second-line therapy. When administered with vinorelbine, the combination was also active and well tolerated in anthracycline- and taxane-pretreated patients. Combining PBCs with etoposide or nucleoside analogues showed moderate activity, yet high toxicity in the case of etoposide. The overall results for the combination with anthracyclines were disappointing. Addition of trastuzumab to PBC combinations showed remarkable activity and good tolerability in patients with HER2/neu overexpression. The use of cisplatin or carboplatin alongside novel targeted therapeutics for patients with triple-negative MBC seems promising and is being further evaluated. The use of PBCs against MBC requires careful patient selection and combination with the right chemotherapeutic agent. Copyright © 2012 S. Karger AG, Basel.
Abbas S.,Saida University |
Benchohra M.,University Djilali Liabes
Nonlinear Analysis: Hybrid Systems | Year: 2010
In this paper we investigate the existence of solutions for a class of initial value problems for impulsive partial hyperbolic differential equations involving the Caputo fractional derivative by using the lower and upper solutions method combined with Schauder's fixed point theorem. © 2009 Elsevier Ltd.
Farhat F.S.,Saida University |
Houhou W.,Saida University
Therapeutic Advances in Medical Oncology | Year: 2013
The search for innovative therapeutic agents in non-small cell lung cancer (NSCLC) has witnessed a swift evolution. The number of targeted drugs that can improve patient outcomes with an acceptable safety profile is steadily increasing. In this review, we highlight current drugs that have already been approved or are under evaluation for the treatment of patients with NSCLC, either in monotherapy or combined therapy for both the first- and second-line settings. Experience with drugs targeting the vascular endothelial growth factor and its receptor, as well as the epidermal growth factor receptor is summarized. Moreover, we provide an overview of more novel targets in NSCLC and initial experience with the respective therapeutic agents. © The Author(s), 2013.
Terfous A.,IMFS |
Hazzab A.,Saida University |
Powder Technology | Year: 2013
This paper presents a relationship for calculating the drag coefficient of a spherical particle. The results obtained were validated using experimental data, including comparison with results from other relationships such as certainty analysis. The validation indicated that the proposed relationship is easier to apply and produces the best results. In addition, a relationship based on the characteristics of both the fluid and the particles was established to calculate directly the settling velocity of a spherical particle in a fluid at rest. The settling velocity values obtained with the proposed relationship were validated using experimental data and the model proved to be reliable and precise. © 2013 Elsevier B.V.
Bouchikhi A.,Saida University
Plasma Science and Technology | Year: 2012
This paper presents an investigation of a DC glow discharge at low pressure in the normal mode and with Einstein's relation of electron diffusivity. Two-dimensional distributions in Cartesian geometry are presented in the stationary state, including electric potential, electron and ion densities, longitudinal and transverse electrics fields as well as electron temperature. Our results are compared with those obtained in existing literature. The model used in this work is based on the first three moments of Boltzmann's equation. They serve as the continuity equation, the momentum transfer and the energy equations. The set of equations for charged particles presented in monatomic argon gas are coupled in a self-consistent way with Poisson's equation. A parametric study varying the cathode voltage, gas pressure, and secondary electron emission coefficient predicts many of the well-known features of DC discharges.
Si Tayeb T.,Saida University
European Space Agency, (Special Publication) ESA SP | Year: 2016
The last thirty years, there is a real dynamic change of land cover with intensive degradation of the natural vegetation especially in arid zone. Indeed, the adverse effects of drought periods from the year 1970 combined with population growth and economic conditions experienced by the country in the 1980s have greatly upset the delicate balance of the natural environment. These adverse effects may result in partial or total disappearance of some natural ecosystems. The objective of this work is to study the distribution of plant formations that constitute the ecosystem typical of west Algeria and their dynamics in time and space, as well as to develop a method to monitor the degradation process and a system capable of effectively protecting areas classified for their plant and animal species. The Landsat satellite images were used to map the vegetation of the study area at a scale of 1:200,000. A comparison was then made between the map obtained from satellite images (Landsat 8) of 2014 and (Landsat 5) of 1987. The results show the following main trends in the distribution patterns of steppe species, a strong decrease of land occupied by steppe of Stipatenacissima and steppe of Artimesiaherba-alba, witch replaced by three taxa Thymelaeamicrophylla, Salsolavermiculata and Peganumharmala. Steppe of Artemisia herbaalba has been transformed by steppe of. taxa Thymelaeamicrophylla, Salsolavermiculata and Lygeumspartum. Woody species such as Quercus ilex and Juniperusphoenicea are characterized by a large regression.