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Waste rock materials are becoming widely used in road pavement and building constructions in many countries. In this work, experimental laboratory tests were carried out on the waste rock produced from the extraction of the phosphate in the Kef-Essenoun mine, to study the performance of road pavement foundations built with these types of material. Two types of waste, namely phosphatic limestone (type 1) and limestone (type 2), were initially tested to determine the most suitable one to be used in pavement structures. The characterization tests showed that the presence of carbonate-fluorapatite and carbonate-fluorapatite, and calcite, dolomite, and quartz are predominant in phosphatic limestone and limestone, respectively. The Los Angeles Abrasion (LA) and Micro-Deval (MD) values range from 59.9% to 90.4% and 42.05% to 86.31% for phosphatic limestone and from 43.64% to 95.88% and 38.25% to 75% for limestone. The CBR values of type 1 and type 2 waste were found to be 10.5% and 18.7% respectively. The results show that these materials, classified as B42ts and B42s respectively, could be used cautiously in capping layers and pavement backfilling materials. Furthermore, they must be treated with a hydraulic binder such as cement in order to improve their physical and mechanical properties.

The spinel MgFe2O4 synthesized by sol gel method, was characterized by physical and electrochemical methods. The thermal analysis (TG) gives an optimal synthesis temperature of 650 °C where the X-ray diffraction pattern exhibits a single phase crystallizing in a cubic symmetry (Space Group: Fd $$\stackrel{-}{3}$$ m) with spherical crystallites (~ 0.45 µm). The morphology observed through the SEM image shows elliptical and spherical grains of ~ 0.8 µm. The spinel possesses a direct optical transition (2.16 eV) due to electrons transfer Fe3+: d−d transition, coming from the crystal field splitting in agreement with the red color. The low electrons mobility is assigned to a narrow conduction band of Fe3+: 3d parentage with activation energy (0.14 eV) in conformity with a conduction mechanism by small polaron hopping. The semi-logarithmic plot confirms the chemical stability of oxide. Unlike other spinels, the capacitance plot exhibits n type conduction confirmed by chrono-amperometry with a flat band potential (Efb) of 0.27 V. The electrochemical impedance spectroscopy displays a semi-circle attributed to the bulk behavior. As application, the photodegradation of methylene blue (10 mg L− 1) was successfully on the spinel suspension; 87% are eliminated after 2 h of exposure to sunlight irradiation.

This chapter aims to address the marketing information system MIS and its role in the face of marketing crises, especially in light of the ongoing changes and what needs him to current information about the surrounding environment. The study concluded that the marketing information system MIS plays an active role in the management of the marketing crisis by properly exploiting the huge amount provided by big data of classified data, and stored according to a database that helps to speed the flow to allow for the response of these crises and predict.

International audience; Rare earths are critical elements in our modern societies and the ever-increasing demand raises fears of supply risks in the coming years. This work dealt with the feasibility of extracting rare earth elements (REEs) from an industrial waste product from the exploitation of phosphate ores of “Djebel Onk” in Tébessa eastern region of Algeria. The solid residue was first leached at room temperature with three different inorganic acids (HNO3, H2SO4 and H3PO4) at various concentrations and leaching times. It was possible to recover almost 100% of La, Ce, Eu, Gd and Y with HNO3 3 N in 24 h. However, only about 10% of Yb were leached. The leachates were further treated with two organophosphorous extractants, trioctylphosphine oxide (TOPO) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) at various concentrations in chloroform. A virtually total extraction of Eu, Gd, Y and Yb was achieved with TOPO at 0.3 M. The extraction efficiency of light rare earth elements (LREEs), La and Ce, was only 38 and 55%, respectively. Very good selectivities between heavy rare earth elements (HREEs), and LREEs as well as between medium rare earth elements (MREEs) and LREEs were obtained but TOPO was unable to selectively separate HREEs from MREEs. Although D2EHPA led to lower REEs extraction efficiency than TOPO, it showed interesting performance for the selective separation of REEs into three fractions corresponding to LREEs (La and Ce), MREEs (Eu and Gd) and HREEs (Y and Yb).

In this paper, an experimental facility is implemented with the aim of improving the performance of internal combustion engines working at low ambient temperatures. Pollutant emissions and fuel consumption are one of the major issues that automotive engineers have to face. Cold engine start and warming up analysis have become important topics for researches. In this work, an exhaust heat recovery system for a diesel engine has been proposed as a solution to cold operation negative effects. The energy obtained from the exhaust gases was used to increase the intake air temperature. The experiments were carried out in transient load conditions at three different levels of ambient temperature (up to -7ºC). Exhaust heat recovery was combined with different strategies of exhaust gas recirculation. Intake air heating results with the heat recovery system show a reduction of 65% in unburned hydrocarbons, 40% in carbon monoxide and 10% in fuel use compared to standard air-air intercooler., This research has been partially financed by the Ministerio de Economia y Competitividad of Spain, through project IPT-370000-2010-022 'Investigacion y desarrollo de tecnologias de EGR adaptadas a las nuevas arquitecturas y requerimientos de refrigeracion en motores diesel sobrealimentados para automocion (HIREFIRE)'. The authors gratefully appreciate this support. Authors want to acknowledge the "Apoyo para la investigacion y Desarrollo (PAID)" grant for doctoral studies (FPI S2 2015 1062).

Current diesel engines are struggling to achieve exhaust emissions regulations margins, in certain cases penalizing the fuel consumption. The exhaust gas recirculation (EGR) continues to be employed as a technique to reduce NOx emissions. EGR dispersion between cylinders is one important issue when a high pressure (HP) loop is used. Different techniques have been developed in order to analyze the EGR dispersion between cylinders in an engine test bench. In this paper a methodology using the in-cylinder pressure was developed. The in-cylinder pressure was used to calculate a heat release law and combustion parameters that were used to analyze the EGR dispersion between cylinders. Engine test measurements at three different engine speeds and with three different HP-EGR configurations were performed in order to assess the developed analysis methodology. NOx emissions and fuel consumption were also compared between the different HP-EGR configurations to complete the analysis. The developed methodology was successfully used in three different operating conditions for three different HP-EGR configurations, showing the relation between the decrease in EGR dispersion between cylinders and the decrease in NOx emissions, while maintaining and, in some points, improving the fuel consumption.

In the present work, we introduce the particle swarm optimization called (PSO in short) to avoid the Runge-s phenomenon occurring in many numerical problems. This new approach is tested with some numerical examples including the generalized integral quadrature method in order to solve the Volterra-s integral equations