Homotopy Perturbation Transform method for solving the partial and the time-fractional differential equations with variable coefficients

In this paper, we present the exact solutions of the Parabolic-like equations and Hyperbolic-like equations with variable coefficients, by using Homotopy perturbation transform method (HPTM). Finally, we extend the results to the time-fractional differential equations. Keywords: Caputo’s fractional derivative, fractional differential equations, homotopy perturbation transform method, hyperbolic-like equation, Laplace transform, parabolic-like equation

Optimal design of wind energy generation in electricity distribution network based on technical-economic parameters

In order to satisfy electricity customers and avoid some environmental constraints and problems, the transition to renewable energy sources has become increasingly important given their advantages and benefits, such as reducing pollution and improving the reliability of the targeted distribution system. In this paper, several state-of-the-art metaheuristic optimisation algorithms are used to investigate the optimal setting and sizing of wind turbines (WTs) when connected to the electricity distribution network (EDN). The selected algorithms were implemented to optimise and minimise a multi-objective function (MOF) considered as the sum of the techno-economic parameters of total active power loss (TAPL), total voltage deviation (TVD) and investment cost of the WTG (ICWTG) when the daily uncertainties and variations of the load-source powers are taken into account. The effectiveness of the selected algorithms was validated on the two standard test systems IEEE 33-bus and 69-bus. The simulation results in this paper showed the superiority of the Gorilla Troops Optimizer (GTO) algorithm compared to other new metaheuristic optimisation algorithms in terms of providing the best optimised results. Accordingly, the GTO algorithm showed excellent effectiveness and robustness in determining the optimal setting and sizing of the WTG units in EDN. Thus, the daily active power losses were reduced to 1,415 MWh for the first test system and 1,072 MWh for the second test system, while also improving the bus voltage profiles and favouring the investment costs of the installed WTG units, all with daily uncertainties in terms of load demand and WTG power variations

Trend Assessment by the Mann-Kendall Test and the Innovative Trend Analysis Method (North-West Algeria)

In this article, a trend study, in two watersheds Coastal-Oran and Macta (North-West of Algeria), is carried out using monthly and seasonal rainfall during the period 1975–2015 at 38 stations. Mann-Kendall (MK) and Innovative Trend Analysis (ITA) methods are applied comparatively. The aim of this study is to verify if the trend detection ability is the same in both methods. Monthly rainfall analysis by the MK test shows that 82% of the stations have no significant trends. In contrast, the ITA method detects positive (negative) trends in 56% (33%) of stations in the low rainfall component, 53% (40%) in the average and 41% (58%) in the high rainfall. On a seasonal scale, the MK test still not aware of trends in 75% of the studied stations, while the ITA shows that 63% (31%) of stations with increasing (decreasing) trends. Studying the rainfall trend, using the ITA and Mann-Kendall methods, in the same area can help to understand past variations and therefore extrapolate the results to other areas with the same climate. This is a crucial step in managing climate-related issues. In addition, the ITA detects hidden sub-trends in the low, medium and high components that the MK test does not, which shows the superiority of the ITA method over MK method

Damage analysis and mechanical behavior of the low voltage overhead power cables dedicated to distribution network

Since the onset of electrical systems, electrical cable was the first physical support for passing an electric current to flow. Until now, the power cable is still valid and has undergone intrinsic more severe modifications to adapt with the electrical and environmental constraints. However, mastering the reliability of overhead lines of electric power long distances through generally different parts of their relief (topography and altitude), climate (temperature, pressure, wind) their environment (industrial areas, coastal areas) has become increasingly important. Therefore, the equipment power transmissions are exposed to various constraints, among these, the degradation of connections and electrical aging weapons which are recognized as major factors causing the faults stored on airlines, and thus appear as very important factors in the quality and reliability energy transport. The purpose of our work is to optimize the control performance of the ducts from the overhead electrical distribution networks generally and especially aging degradation. For this we will look at details of the various mechanisms and processes involved in the thermal aging of solid insulation in general and in particular synthetic sheaths. We then discuss the experimental part includes the cable and used test devices and complete the study by discussing results

FTIR study of HDPE structural changes, moisture absorption and mechanical properties variation when exposed to sulphuric acid aging in various temperatures

The aging of high density polyethylene (HDPE) when exposed to sulphuric acid solution at room temperature, 40°C or 60°C was studied. Sorption kinetics was studied through water absorption rate response at different temperatures. Similarly, diffusion coefficients of solvent molecules in the HDPE samples were determined. The activation energy and the mixing enthalpy were also deduced. The structural modifications and chemical changes by the application of Fourier transform infrared spectrophotometry (FTIR), mainly polymeric chain breaking and branching have been studied

Remappings - the Making of European Narratives

How narratives emerge, unfold and impact across Europe today, and how they contribute to redrawing our maps of Europe

Pour une modélisation linguistique des modèles d'écriture des lycéens apprenants scripteurs

Towards a linguistic modeling of writing models of high school learners writers Abstract Focusing on writing from a didactic aspect is to present it as a complex activity that requires the mobilization of much knowledge and a multitude of procedures. Writing represents a language phenomenon, it becomes a language in the fullest sense and a new order of language practices is established that some call it scriptural (Peytard 1970 Dabène 1987). Our purpose is to analyze the final product, the result of the editorial process (SC Thomas, 2000). In fact, we present the study and analysis of a corpus which presents the written productions of High school learners that reflect their actual skills. It is a question of observing the linguistic modeling required for the learners' written productions that rely on relevant parameters of semantics , cognitive psychology ( Fayol, 1996) and the socio-cultural dimension ( Dabène 1996). Do these processes, practiced by learners writers, provide a guarantee of success valuing a written production? We then examine the transposition of models mentioned in the written productions and configurations of writers with regard to their scripts. Finally, we conclude with the clarification of editorial measures offering insight into writing as a recursive activity evolving through the support models that require recurrences depending on the nature of the written production. Educational recommendations, based on all observations are advanced to locate the practical framework of learners/writers writing activities.Se focaliser sur l'écriture sous un angle didactique, c'est la présenter comme une activité complexe qui nécessite la mobilisation de nombreuses connaissances et une multitude de procédures. Nous présentons l'étude et l'analyse d'un corpus présentant les productions écrites des lycéens apprentis scripteurs afin de rendre compte de leurs compétences réelles. Il s'agit d'observer les modélisations linguistiques requises pour les productions écrites par des apprenants scripteurs. Nous examinerons ensuite la transposition des modélisations évoquées dans les productions écrites et les configurations des scripteurs à l'égard de leur écrit. Enfin, nous conclurons par la mise au point des dispositions rédactionnelles permettant d'entrevoir l'écriture comme une activité récursive en évolution constante à travers la prise en charge des modélisations qui requièrent des récurrences en fonction de la nature même de la production écrite

Les aspects cognitifs associés à l'explication

International audienceLe cadre cognitif de l'explication s'appuie sur un certain nombre de points qualifiés de mécanismes nécessaires à la compréhension de toute explication. Il ne s'agit pas de prescrire, dans cette optique, ce que doit appréhender le demandeur de l'expli-cation mais d'observer et de déterminer les processus mentaux qui sont nécessaires à la démarche explicative. Notre article se veut une réflexion permettant de montrer qu'il n'est pas aisé de solliciter une explication sans pour autant savoir qu'il s'agit de faire intervenir un raisonnement difficilement maîtrisable de la part de celui qui reçoit l'explication. Abstract The cognitive framework of the explanation is based on a number of points qualified as mechanisms necessary to understand any explanation. It is not a question, in this context, of prescribing what the seeker for explanation must apprehend, but it's, rather, a matter of observing and determining the mental processes that are necessary for explanatory approach. This article is a reflection to show that it is not easy to seek an explanation without knowing that it is a question of involving reasoning that it is hardly mastered by the one who receives the explanation